Plug bar for seamless tube mills



Oct. 24, 1933. J BURNS PLUG BAR FOR SEAMLESS TUBE MILLS Filed Aug. 4,1931 3 Sheets-Sheet 1 y I I HlP RN ll/62!? 06L 1933- F. J. BURNS PLUGBAR FOR SEAMLESS TUBE MILLS Filed Aug. 4, 1951 3 Sheets-Sheet 2 1 WHWZfl w 11 J INVFNTOR a m I F. .1. BURNS PLUG BAR FOR SEAMLESS TUBE MILLSFiled" Aug. 4, 1931 3 Sheets-Sheet 5 INVENTOR Patented Oct. 24, 1933,UNITED STATES PATENTOFFICE 12 Claims.

My invention relates to the production of seamless pipe and, inparticular, to mechanism for handling the plugs or balls removablysupported by a mandrel rod for cooperation with reducing rolls in theformation of pipe.

According to present methods of manufacturing seamless pipe, a piercedbillet is fed between reducing rolls. A mandrel rod or plug rod extendsinto the pass and is adapted to removably support a plug or ball forforming the interior of the pipe. When the pipe has passed over the ballonto the mandrel rod, the plug or ball must be removed from the rodbefore the pipe is backed off the mandrel. After the pipe has beenbacked off, it is necessary to replace the ball before another pipe ispassed between the rolls.

The manual insertion and removal of the plugs, obviously, is a laborioustask, and it is one object of the present invention to provide means for20 automatically handling the plugs with a minimum of effort. Inaccordance with the invention, I provide a mandrel rod with anextensible plunger adapted to reach out and seize a plug positionedadjacent the end of the rod. Retraction of the plunger carries the plugback to a position slightly spaced in advance of the end of the rod. Aspring is contained within the rod in position to be compressed by theplug when the latter is engaged by a pierced billet passing between therolls. After the billet passes completely over the plug, the compressedspring forcibly removes the plug from the end of the rod.

A discharge chute is provided for the plug leading to a restoring devicewhich restores the plug properly positioned to a point adjacent the endof the plug rod from which it may again be seized by the plunger.

In accordance with a modification of the invention, the plug is adaptedto engage the end 01' 40 the rod firmly before the pierced billetengages the plug. :After such engagement, a spring within the rod iscompressed and di spliarges the plug as, soon as the pipe has passedover the plug.

In accordance with another form of the invention, the compression springis mounted in the plug itself. This modification is otherwise similar tothe form of the invention first mentioned.

For a complete understanding of the invention,

50 reference is made to the accompanying drawings,

in which Figure 1 is a sectional view through a seamless mill showingthe reducing rolls, a. plug rod, a plug thereon, and a pierced billetpassing over the plug 55 between the rolls,

Figure 2 is a similar view of a modified form of the invention,

Figure 3 is a similar view of a further modified form of the invention,

Figure 4 is a sectional view similar to Figure 1 to reduced scale,showing parts in elevation and illustrating diagrammatically the meansfor handling the plugs,

Figure 5 is a sectional view to enlarged scale, showing a detail, and

Figure 6 is a view similar to Figure 4, showing a modified form of meansfor handling the plugs.

Referring now in detail to the drawings and, in particular, to Figures 1and 4 for the present, a seamless mill comprises a pair of reducingrolls 10 having grooves 11 for engaging a pierced billet 12 externally.Guides 13 direct the billet between the rolls 10.

For forming the interior of the billet and sustaining the pressureapplied by the rolls 10, a plug 14 is supported in the roll pass on aplug rod 15. The rod 15 is hollow and is supported at its rearward endby any suitable means (not shown). The plug rod, however, must be longerthan the longest pipe length to be rolled.

The plug 14 comprises a hemispherical portion 16 bored out centrally toreceive a stud 17 having an integral flange 18. The hemisphericalportion 16 is secured to the stud 17 between the flange 18 and a cotterpin 19. The hemispherical portion 16 of the plug is recessed at 20 andis provided with a removable rim 21 seated in the recess 20. The rim 21engages the billet directly for supporting and reducing the wallthereof. The function of the portion 16 is to provide support for therim 21. The latter, of course, is made of hardened steel and may beremoved for redressing or replacement. The rear end of the stud 17 isbored out at 22. The bore 22 is provided with axial gripping springs 23bent inwardly of the bore.

The front end of the rod 15 is closed by a bell v or cup 24 providedwith a compression spring 25. The spring 25 carries a collar 26.Slightly to the rear of the front end of the casting a cylinder 2'7 ispositioned. A piston 28 is adapted to reciprocate in the cylinder underfluid pressure to actuate the plunger 29 which traverses the bell 24 andthe spring 25 axially to enter the bore 22 in the rear end of the stud17. The springs 23 provide a firm grip of the plug on the plunger 29.

Supply and exhaust lines 30 are connected to opposite ends of thecylinder 2'7 and a conduit 31 supplies cooling fluid to the interior ofthe 110 rod 15. Packing glands 32 provide fluid-tight connectionsbetween the plunger 2a, the bell 245 and the cylinder 2'7.

A receiving chute 33 (see Figure 4) is provided adjacent the entranceside of the rolls l0. chute 33 comprises a pivoted plate 34 ha sideguides 35 thereon, a reversing pocket 36 and a delivery mouth 37. Thepocket as and the mouth 37 are supported rigidly on any convenientstructure and the plate 34 is pivoted to the mouth 37 at 38. Thedelivery mouth 37 is provided'with pivoted retaining jaws 39 having acommon operating mechanism including a lever c0 and a link ll. A spring42 normally maintains the jaws in retaining position.

A cylinder 43 is provided with a piston rod 4 carrying at its upper enda seat 45 for a plug such as that described in detail in Figure 1. Theseat 45 carries a roller as for engaging the operating lever 40 of theretaining jaws 39. The seat also carries a. cam member 4:? for actuatingthe pivoted plate as by engagement of the roller 48 thereon when thepiston rod 44 is elevated as indicated in dotted lines in Figure-4.

In describing the operation of the plug-operating mechanism shown inFigure l and the plug-handling mechanism shown in Figure 4, it will beassumed that conditions are as illustrated insaid figures. Under theseconditions, the billet 12 is being fed between the rolls 10 and is beingreduced, by the cooperation of the rolls with the plug, to pipe form. Aswill be apparent in Figure 1, the plunger 29 is withdrawn and the spring25 is compressed by engagement of the rear end of the stud I'lwith thespring collar 26.

When the billet 12 has passed entirely over the plug and onto themandrel rod 15, the pressure against the plug being released causesspring 25 to expand forcibly and discharge the plug from the end of theplunger 29. It may be desirable at this time to apply back pressure tothe piston 28 to prevent it being drawn forward with the plug. As theplug is discharged from the plug rod by the spring, it falls or slidesdownwardly onto the plate 34. as indicated by the dotted line position49, and descends between the guides 35 to delivery mouth 37. It will beassumed that the piston rod d4 at this time is raised above its bottomposition so that the jaws 39 will be in plugretaining position. V

If the piston rod 44 is now permitted to descend,

the engagement of the roller 46 carried therebywith the operating lever40 of the retaining jaws 49, causes the latter to open and release theplug held thereby in the position indicated at 51, so

that it falls or slides downwardly into the seat 45 as shown at 52. Whenthe ball has reached the position 52 it is ready to be restored to aposition 53 adjacent the end of the plug rod 15. If desired, of course,a plurality of. plugs may be used and, if so, the piston 44 will beraised by the admission of fluid under pressure to the cylinder d3 aboutthe time a plug is discharged from the rod aeegsrr the chute as from theposition 49 to the positions to and 51.

-tl7hen the piston rod id has reached the upper t of its movement andthe plug has been raised to the position 53, fluid is admitted to thecylinder 27 (see Figure l) to advance the plunger 29 so that the end ofthe latter enters the bore 22 in the end of the stud 17 of the plug. Theplunger, or course, may be operated by a mechanical drive instead of byfluid pressure. It establishes a grip on the plug by means of thesprings 23. The piston rod dd may then be lowered slowly and the plunger29 retracted by supp fluid under pressure to the forward end of thecylinder 27. When the plunger 29 has reached the rearward limit of itstravel, the plug is spaced slightly in advance of the end of the rod 15.If a pierced billet is now fed through the rolls, the engagement of thebillet with the plug will force the latter rearward so that the stud 17engages the collar 26 to compress the spring 25. When the end of thebillet has passed over the plug, the spring will forcibly eject thelatter as previously described. By the time the billet has been electedfrom the plug rod, the piston rod 4% has been lowered so that anotherplug has been positioned on the seat 45 and is ready to be raised to theposition 53 where it can be engaged by the plunger 29. This cycle ofoperations, obviously, may be repeated indefinitely.

Referring now to Figure 2, a slightly modified form of the invention isillustrated. This form oi the invention is similar in general to thatalready described and the same reference numerals will be used inreferring to corresponding parts thereof. The only featuredistinguishing the modification of Figure 2 from that shown in Figure 1is the fact that the cylinder 27 within the plug rod 15 operates a shortplunger 54 having a head 55 which is adapted to engage the rear end ofthe spring 25. Since the plunger 54 does not extend through the end ofthe rod 15, the plug must be positioned in the end of the rod manually.When this is done, the plunger 54 is preferably withdrawn. The plug,therefore, seats firmly against the end of the rod 15. There is,therefore, no clearance between the plug and the end of the rod when thepierced billet is advanced to the rolls and engages the plug. The plugis firmly supported at all times and there is no possibility of itfailing to enter the billet properly.

After the billet has entered the rolls, I operate the plunger 54 tocompress the spring 25 so that, as soon as the billet has passed throughthe rolls and on of the plug, the compression of the spring willimmediately discharge the plug from the end of the rod 15. Y

The plug-handling mechanism shownin Figure 4, obviously, may readily beused with the modification of the plug-operating mechanism shown inFigure 2, except that the plugs must be moved manually from the position53 of Figure 4 into the position shown in Figure 2. This can be done inan obvious manner with little efiort.

Figure 3 illustrates a still further modification of the invention whichlikewise has many features similar to the modification shown inFigure 1. As shown in Figure 3, this modification of the inventionincludes a plug similar to that shown in Figure 1, except that it isbored to receive a hollow stud 17'. A compression spring 25' iscontained in the hollow stud 17 and is provided with a collar 26'. Theplunger 29 is adapted to be actuated, as already described, by thecylinder 2'7 in the plug rod 15. When the plunger 29 is advanced itseizes the plug as already described and returns it to a position incontact with the end of the rod 15. A billet is then fed through therolls and engages the plug which is firmly braced by its immediatecontact with the end of the rod. After the billet has entered the rolls,the plunger is advanced slightly to compress the spring 25. When thebillet has passed over the plug, the compression of the spring issufficient to force the plug off the end of the rod. It is then disposedof and restored to position for replacement by the means shown in Figure4.

The modification shown in Figure 3 thus combines the features of theforms of the invention illustrated in Figures 1 and 2. In Figure 1, theplug is not in direct contact with the end of the rod, but the plungerserves to pick up the plug at the beginning of a pipe forming operation.In Figure 2 the plunger does not pick up the plug, but the latter issupported in direct engagement with the end of the rod when the billetenters the rolls. In Figure 3, the plug is also in direct contact withthe end of the rod when the billet enters, but the plunger is operableto pick up the plug and to compress the discharge spring. In Figure 1the discharge spring is compressed by the movement of the plug whenengaged by the advancing billet.

In the event that it is not desired to rely solely on the springs shownin Figures 1, 2, and 3, for ejecting the ball from the plug rod, I haveprovided means for positively removing the ball from the rod. Such meansare illustrated in Figure 6. The rolls 10, the pipe 12, the plug 14',the plug rod 15, and the plunger 29 are indicated in Figure 6 by thesame reference numerals previously employed.

The plug handling mechanism includes a chute 60 having a top door 61 anda bottom door 62. The door 61 is pivoted at 63. When the pipe 12 haspassed completely over the plug 14 and it is desired to remove thelatter, the plunger 29 is extended as shown in Figure 6. Acylinder 6 1beneath the chute 60 is provided with a piston having a fork and aroller 66. When the piston in the cylinder 66 is elevated, the fork 65passes through an opening 67 in the floor of the chute 60. The roller 66engages the door 61 and shifts it to the dotted line position 68.Simultaneously, the fork 65 engages the plug 14, whereupon withdrawal ofthe plunger 29 permits the plug to fall on to the door 61. The latter isprovided with side guides 69, so that, when the fork 65 is lowered, theplug is permitted to slide down into the chute 60.

A detent 70, which is reciprocated by means to be described hereinafter,is provided for retaining the plug within the chute 60.

The bottom door 62 of the chute 60 is pivoted at 71. An electromagnet'72 and. a linkage 73 are provided for shifting the door 62 to itsdotted line position 74. The linkage 73, through a lever '75 is adaptedto operate the detent '70. A latching member 76 serves to maintain thedetent '70 in its upper position as long as the magnet '72 remainsenergized.

The means for restoring the plug to its position on the plug rodincludes a cylinder 77 in which a piston reciprocates. The piston isprovided with a seat 78 for the plug 14. When the seat 78 is elevated bymeans of the piston, it traverses an enclosing chamber 79 having apivoted door 80. When the piston is first raised, a contact lever 81 isactuated by a spring 82 to close the circuit for the electromagnet '72which thereupon closes the door 62 and raises the detent '10.

On further upward movement of the seat '78, a projection 82 thereonengages a lever 83 having pivotal connection with a slotted link 84. Theupward movement of the seat 78 swings the lever 83 to one of its extremepositions, shown in dotted lines in Figure 6.

As the upward movement of the piston in the cylinder '77 is completed,the door 80 is engaged by the ball on the seat '78 and is thrust open toits dotted line position 85. When the piston is lowered, the projection82 again engages the end of the lever 83 and, by means of the link 84,actuates a plunger 86 to close the door 80. The door 80 iscounterweighted at 87 to insure closing.

The cylinders 64 and '77 are adapted to be con- Erolled manually bymeans of suitable valve conro s.

The complete cycle of operations will now be described on the assumptionthat the initial conditions are as represented in Figure 6. The pistonin the cylinder 64 is first raised so that the door 61 is shifted andthe plug 14 is engaged by the fork 65. The plunger 29 is then withdrawnand the plug falls onto the door 81. The piston in the cylinder 77supporting a duplicate plug 14 on the seat 78 is then raised slightly topermit the energization of the magnet 72 by the operation of the contactlever 81. The energization of the magnet 72 causes the door 62 to beclosed to its dotted line position 74, thus providing a smoothcontinuous interior surface for the chamber '79 and forcing the plug 14into position on its seat in case it is not properly placed thereon. The

energization of the magnet 72 also raises the detent '70 and permits thelatter to be latched in its upper position by the latch 76.

The piston in cylinder 64 is then lowered to restore the door 61 to thesolid line position. The withdrawal of the fork 65 from the plug 14permits the latter to slide down the chute 60 until it engages thedetent 70. The upward movement of the piston in'the cylinder 77 is thencontinued. The engagement of the projection 82 on the seat 78 swings thelever 83 to its extreme position but does not operate the plunger 86because of the lost motion permitted by the slot in the link 34.

As the upward movement of the plug 14 through the chamber '79 iscompleted, the door 80 is swung open and the plug is positioned forengagement with the plunger 29 when the latter is again extended. Whenthe plug has been picked up by the plunger, the piston in the cylinder7'7 may be retracted. The plunger 29 is also withdrawn, carrying with itthe plug 14. As the projection 82 engages the end of the lever 83, thelatter is actuated to raise the plunger 86 and swing the door 80 fromits open position 85 to the closed position. Further downward movementof the piston causes the opening of the circuit for the magnet '72,which is thereby deenergized to permit the door 62 to fall open, asshown in solid lines in Figure 6, and to lower the detent 70, the latch76 having been withdrawn, The lowering of the detent permits the plugdelivered to the chute 60 to pass downwardly onto the seat 78 so that itcan be replaced on the plunger 29 by means of the cycle of operationsabove described.

A spraying device 88 is incorporated in the top of the chute 60 for thepurpose 01' cooling the plugs while they are sustained by the detent'70.

It will be apparent from the foregoing description that I provide meansfor automatically handling the removable plugs of a seamless pipe millwith little eilort and with considerably greater rapidity than ispossible with present methods of handling. The apparatus shown canconveniently be controlled by one operator who can be stationed at alocation permitting him to view the. operation closely. The inventioncontributes to the production of seamless pipe at high speeds becausethe delays incident to the insertion and removal of plugs according topresent methods are eliminated. The insertion of the plug, as well asits removal, is accomplished in a minimum of time and with practicallyno efiort.

Although I have illustrated and described certain specific modificationsof the invention, it will be apparent that many changes in the structureherein described may be made to adapt the invention for variousinstallations. The invention however, is not limited to the exact formdisclosed, but includes also any changes in the details thereof whichmay be made without departing from the spirit of the invention as setforth in the appended claims.

I claim:

1. In a removable plug for seamless mills, a spherical portion, a studsecured thereto, a bore in said stud for receiving a plunger, and meansin said bore for gripping said plunger.

2. In a seamless pipe mill, the combination with a plug rod, a plungerreciprocable therein for seizing a plug adjacent the end of the rod andmoving it into engagement with the end of the rod, of a spring withinthe plug adapted to be compressed by said plunger when the plug has beenengaged by a billet passing through the mill.

3. In a seamless tube mill, the combination with reducing rolls, amandrel and a plug adapted to lie between the rolls engaging saidmandrel for support against rolling thrust, of means for supporting aplug adjacent the mandrel, an extensible plunger for engaging the plugwhile resting on said means and moving it to working position againstsaid mandrel, and power means for extending and retracting the plunger.

4. The combination with a seamless pipe mill including reducing rolls, amandrel rod for receiving rolled pipe, and water-cooling means for therod, of an extensible plunger within the rod adapted to engage a plug tosupport it at the end of said rod, power means for operating the plungerto eject the plug from the mill after passage of the pipe onto the rod,means for removing the plug from the plunger, and means for positioningthe plug adjacent the mill after the pipe has been removed therefrom,said plunger, when extended by said power means, being effective toengage and support said plug and, when retracted, to restore it to theend of the rod.

5. In a seamless mill, a plug rod, water-cooling means therefor, a plugremovably carried thereby, means for receiving the plug on removal fromthe rod, means for restoring the plug to a position adjacent the end ofthe rod, an extensible plunger in the rod and power means for extendingthe plunger into engagement with a plug' on said restoring means, saidplunger, when retracted,

mantra plunger in the rod for removing the plug from the rod, means forengaging the removed plug, means for restoring it to a point adjacentsaid rod, and power means for extending the plunger to engage the plugwhile supported on said restoring means, and for retracting the plungerto replace the plug against the rod.

7. In a seamless tube mill, a plug rod, a reciprocable plunger carriedby said rod, a plug removably mounted on said plunger, means forengaging said plug when said plunger is extended, for removing the plugfrom the plunger on retraction of the latter, and means for restoringthe plug to a position adjacent the end of the rod and in axialalinement therewith, power means for operating the plunger to cause itto extend and engage said plug and for retracting the plug to restore itto its position against the end of the rod.

8. In a seamless mill, a plug rod, a plug removably positioned at theend of the rod, a spring for ejecting the plug, and power operated meansfor compressing said spring after the plug is engaged by an advancingbillet.

9. Means for handling plugs in a seamless tube mill, comprising amandrel having an extensible plunger for supporting plugs thereon, meansfor removing plugs from the plunger, a chute for removed plugs, aretractible stop in the chute,

means for receiving plugs from the chute and restoring them to a pointfor engagement by the plunger on extension thereof, and power means 1 aplug on said supporting means and for retracting it to replace the plugagainst the mandrel.

ll. The combination with a seamless tube mill of a mandrel, a plungerreciprocable in the mandrel, a mandrel plug positioned adjacent themandrel for receiving the plunger, and power means for extending theplunger to engage the plug, and for retracting the plunger to replacethe plug.

12. In a seamless tube mill, the combination with reducing rolls, amandrel adapted to support a removable plug between the rolls againstrolling thrust, and means including a power operated plunger forengaging a plug positioned adjacent the mandrel and positively moving itinto position between said rolls.

FRANK J. BURNS.

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